Dan Wohlfeiler, MJ, MPH, has worked in HIV and STD prevention since 1987. He has focused much of his career on developing structural interventions and policies to reduce HIV and STD prevention and to create healthy environments, particularly those that affect sexual networks and disparities. He is the co-founder and director of Building Healthy Online Communities, a partnership of public health and dating site and app owners, which aims to support the sexual health of people seeking new partners online. He also serves as the Chief of the Office of Policy, Planning and Communications in California’s STD Control Branch. From 1990 to 1998, Dan directed the programs at the STOP AIDS Project in San Francisco, which was the largest organization in the US focusing on HIV prevention for HIV-positive and HIV-negative gay men of all colors and ages. He has also worked in the Global Programme on AIDS at the World Health Organization, and the AIDS Prevention Program of Catalonia. Dan, a former journalist and documentary filmmaker, holds master’s degrees in public health and journalism from the University of California at Berkeley.